The diagnosis and treatment of cartilage tumors of bone are difficult for the orthapaedic surgeon and pathologist because the clinical and biological behavior of the tumor does not always correlate with the histology. Little is known about the biochemistry and metabolism of cartilage tumors. This proposal is based on the hypothesis that the biochemical and metabolic characteristics of the chondrosarcoma may provide a better system for classification and prediction of behavior than the currently available methods and may also provide clues as to newer methods of therapy. This study proposes to prove this hypothesis by analyzing surgically obtained specimens of benign and malignant cartilage tumors by a variety of histologic, histochemical, biochemical and metabolic techniques in an effort to establish a "biological profile" for the lesions. Following obtaining of these data, one or several aspects of the biological profile may be found to serve as a predictor of clinical behavior of the lesion and thus establish biochemical tests which will serve as indicators of the benign or malignant state. On the basis of the biological profile certain techniques of treatment will be studied using in vitro systems. These may serve to find a more effective method of treatment for the malignant cartilage lesions.